1. Field of the Invention
The present invention relates to a solution temperature control device in a cell observation chamber, and specifically to a solution temperature control device in a cell observation chamber adapted to control solutions in the cell observation chamber to be a predetermined temperature in an apparatus used for: for example, determining whether or not cells move in a certain direction by themselves; observing a state where cells move in a certain direction by themselves; measuring the number of cells that have moved in a certain direction by themselves; and isolating cells that move in a certain direction by themselves, that is, an apparatus for detecting cell chemotaxis and for isolating chemotactic cells, and thereby to improve the accuracy of these operations.
2. Description of the Prior Art
There have conventionally been proposed and marketed various kinds of apparatuses for detecting cell chemotaxis and for isolating chemotactic cells. In particular, there has been proposed an apparatus, as described in Japanese Patent Laid-Open Publication No. 2002-159287, adapted to be capable of observing and quantitating the self-based movement of cells precisely and easily using a few cell samples to detect the chemotaxis of the cells due to chemotactic factor or the chemotaxis inhibition of the cells due to chemotactic factor inhibitor. In this apparatus, it is also possible to isolate the cells utilizing the chemotaxis of the cells.
In the apparatus for detecting cell chemotaxis and for isolating chemotactic cells described in the foregoing publication, a cell observation chamber is arranged as follows.
As shown in FIG. 16, the cell observation chamber 00 comprises: a circular shallow dish-shaped bottom support body 01 with a window 01c for observing the movement of cells provided in the center of the bottom part thereof, a glass substrate 08 adapted to be placed on the bottom part 01a of the bottom support body 01; a dish-shaped intermediate support body 02 adapted to be attached to the bottom support body 01 to press and fix the glass substrate 08 from above onto the bottom part 01a by connecting a cover 04 to be described hereinafter to the bottom support body 01 with screws; a substrate 07 and a packing member 010 adapted to be fitted into a rectangular opening portion 02c that is formed in the center of the bottom part of the intermediate support body 02 to be fixed onto the glass substrate 08; a block body 09 adapted to be fitted into the central recessed portion of the intermediate support body 02 to press and fix the substrate 07 onto the glass substrate 08 through the packing member 010 using pressing screws not shown in the figure; and a cover 04 adapted to be attached to the bottom support body 01 through a screw connection to press and fix the block body 09 from above to the intermediate support body 02. The substrate 07 is made of silicon single-crystal material.
The connection between the bottom support body 01 and the intermediate support body 02 is to be made by screwing a male thread 02d formed in the outer peripheral surface of the body part of the intermediate support body 02 into a female thread 01d formed in the inner peripheral surface of the body part of the bottom support body 01 and by a screw connection between the bottom support body 01 and the cover 04. The screw connection between the bottom support body 01 and the cover 04 is to be made by screwing a male thread 01e formed in the outer peripheral surface of the bottom support body 01 into a female thread 04a formed in the inner peripheral surface of the sleeve part of the cover 04. The intermediate support body 02 is to be positioned on the bottom support body 01 by inserting guide pins (not shown in the figure) disposed on the upper surface of the body part of the bottom support body 01 into guide pin receiving holes 02f formed in the lower surface of the flange part 02b of the intermediate support body 02. Also, the block body 09 is to be positioned in the intermediate support body 02 by inserting guide pins 013 disposed on the bottom surface of the intermediate support body 02 into guide pin receiving holes 09a formed in the bottom surface of the block body 09.
Then, in a state where the above components are assembled integrally and used, at least a pair of wells and a flow path for communicating of these wells are to be formed between the substrate 07 and the glass substrate 08. One of these wells is to be provided with cell suspension, while the other thereof is to be provided with chemotactic factor containing solution, so that cells move from one to the other of the wells through the flow path in response to the chemotactic factor. A microscopic observation is to be carried out through the window 01c to observe the state and to measure the number of moving cells.
The injection of cell suspension and chemotactic factor containing solution into one and the other wells that are formed between the substrate 07 and the glass substrate 08 is to be performed using a micropipette through specialized through holes formed, respectively, in the block body 09, the packing member 010, and the substrate 07. After assembling the bottom support body 01, the intermediate support body 02, and the cover 04, an O-ring 011 is to be interposed between the intermediate support body 02 and the glass substrate 08 so that no solution filling the bottom support body 01 leaks. On the other hand, the packing member 010 is also provided between the substrate 07 and the block body 09 so as to be useful in preventing each solution from leaking from the wells and the flow path for communicating of the wells.
Meanwhile, in order to observe the state of cells that move from one to the other of the wells through the flow path and to measure the number of moving cells precisely, it is necessary to control the temperature of the cell suspension and the chemotactic factor containing solution or the mixture containing these solutions filling these sections so as to be suitable for the activity of the cells. Also when it is demanded that the reaction of the cells due to temperature change be measured and analyzed more precisely, it is necessary to control the temperature of the solutions. For these reasons, in this apparatus, the cell observation chamber 00 is adapted to be placed on a heating section composed of heating elements not shown in the figure, and a temperature control device is used to heat these solutions indirectly through the wall of the bottom support body 01 to control these solutions to be a desired temperature while controlling the heating section to be a predetermined temperature.
Since the conventional cell observation chamber is thus arranged in such a manner that the solutions filling the wells and the flow path for communicating of the wells in the cell observation chamber 00 are heated from outside the cell observation chamber 00, for example, indirectly through the wall of the bottom support body 01, and that a temperature sensor is installed outside the chamber, it is not easy to keep the solutions at a desired constant temperature, which makes it inadequate to say that the accuracy in controlling the temperature of the solutions is sufficiently given.    Patent Document 1: Japanese Patent Laid-Open Publication No. 2002-159287    Patent Document 2: Japanese Patent Laid-Open Publication No. 2003-088357